Circulatory System Flashcards
The aorta is an example of what kind of artery?
An elastic artery.
What kind of epithelium surrounds capillaries?
Simple squamous epithelium.
What are the three types of capillaries?
- Continuous. 2. Fenestrated. 3. Sinusoids.
Where are sinusoidal capillaries found? Why?
The spleen and bone marrow because RBCs can get through and be filtered or be put into circulation.
What regulates blood flow to tissues in capillaries?
Precapillary sphincters.
What is each capillary bed fed by?
A metarteriole.
What are three ways that veins get back blood despite having low blood pressure?
- Muscle Pump. 2. Respiratory pump. 3. Valves.
Why do varicose veins occur?
Nonfunctional valves cause blood to pool.
What is collateral circulation?
Alternative pathways for delivering blood to a region of the body.
What is arteriolarterial anastomes?
Collateral circulation provided to many organs and body regions.
Where do lymphatic capillaries receive fluid from?
Leaking capillaries.
Do lymphatic capillaries contain valves?
Yes.
Where do lymph ducts empty fluids?
Into veins in the neck.
How does the diameter of lymph capillaries differ from vascular capillaries?
Lymph capillaries are larger in diameter.
How do the walls of lymph capillaries differ from vascular capillaries?
Lymph capillaries have thinner walls.
How does the permeability of lymph capillaries differ from vascular capillaries?
Lymph capillaries have greater permeability.
How do the walls of lymph vessels differ from veins?
Lymph vessels have thinner walls.
How do the lumens of lymph vessels differ from veins?
Lymph vessels have larger lumens.
Do lymph vessels contain valves?
Yes.
What is lymphedema?
An accumulation of interstitial fluid due to lymphatic drainage issue or lymphatic failure.
What two components is blood composed of?
- Plasma. 2. Formed elements.
What is plasma? What does it contain?
The liquid component of blood. It contains dissolved proteins and other solutes (electrolytes, nutrients, and wastes).
What are formed elements?
Blood cells (red and white blood cells) and the cell fragments (platelets) suspended in the plasma.
What do Red blood cells (erythrocytes) do?
Transport oxygen and carbon dioxide.
What do white blood cells (leukocytes) do?
Component of the immune system.
What are platelets?
Small, membrane-enclosed packets of cytoplasm containing enzymes and clotting factors, proteins that play a role in blood clotting.
What are three proteins found in blood?
- Albumins. 2. Globulins. 3. Fibrinogen.
What are albumins? (2)
- A major contributor to osmotic concentration of plasma. 2. Transport some lipids.
What do globulins do?
Transport ions, hormones, lipids.
What is the function of fibrinogen?
Essential component of clotting system.
What is a serum?
Blood plasma from which clotting agents have been removed.
What synthesizes and releases the vast amount of blood proteins?
The liver.
What is the function of of neutrophils?
Phagocytic; engulf pathogens or debris in tissues.
What are the functions of eosinophils? (2)
Attack anything that is labeled with antibodies; important in fighting parasitic infections. 2. Suppresses inflammation so it doesn’t spread to adjacent tissues.
What is the function basophils? (2)
Enter damaged tissues and release histamine, which dilates blood vessels. 2. Secretes heparin, which prevents blood clotting.
What is the function of monocytes?
Enter tissues to become free macrophages; engulf pathogens or debris.
What is the function of lymphocytes?
Cells of lymphatic system, providing defense against specific pathogens or toxins.
What is hematocrit? What is it a good approximation of?
The percentage of whole blood containing formed elements. A good approximation of the volume of RBCs.
What is the shape of a red blood cells? What is good about this shape?
A biconcave disc with a thin central region and a thick outer margin. It gives an RBC increased surface area.
What are the two categories of leukocytes?
- Granular leukocytes or granulocytes. 2. Agranular leukocytes or agranulocytes.
What is chemotaxis?
The attraction of phagocytic cells to the source of abnormal chemicals in tissue fluids.
What cells are contained within the granualocytes category?
- Neutrophils. 2. Eosinophils. 3. Basophils.
What are the three types of lymphocytes?
- T cells. 2. B cells. 3. Natural killer (NK) cells.
What is the function of T cells?
To enter peripheral tissues and attack foreign cells directly.
What is the function of B cells?
They differentiate into plasma cells (plasmocytes). Plasma cells secrete antibodies that attack foreign cells or proteins.
What is the function of Natural Killer (NK) cells?
They are responsible for immune surveillance and the destruction of abnormal cells.
What determines blood type?
The presence of surface antigens (agglutinogens) in the RBC’s plasma membrane.
What are two lymphatic ducts?
- Right lymphatic duct. 2. Thoracic duct.
How do tunic differ in lymphatic vessels than in veins?
Lymphatic vessel tunics are harder to differentiate that those in vessels.
What are the three layers of a blood vessel? (From outside-in)?
- Tunica Adventitia. 2. Tunica media. 3. Tunica intima.
What is the tunica media important for?
Vasocontriction and vasodilation.
What is the tunica media made up of?
The middle layer that contains concentric layers of smooth muscle tissue supported by a framework of loose connective tissue.
What is a lumen?
The inside space of a tubular structure.
What is the tunica adventitia made up of?
This layer is very thick and is composed chiefly of collagen fibers, with scattered bands of elastic fibers.
What is the tunica intima composed of?
It is composed of the endothelial lining of the vessel and an underlying layer of connective tissue containing variable amounts of elastic fibers.
What do arteries contain in the tunica media that veins do not?
A thin band of elastic fibers, called the external elastic membrane, located between the media and adventitia.
What do arteries contain in the tunica intima that veins do not?
The outer margin of the intima contains a thick layer of elastic fibers called the internal elastic membrane
How do artery vessel walls compare to veins vessel walls?
Artery walls are thicker.
How do artery vessel lumens compare to veins vessel lumens?
Artery vessel walls will contract, constricting the lumen.
How does an artery vessel lining compare to a veins vessel lining?
The endothelial lining of an artery cannot contract, so when an artery constricts, its endothelium folds. Veins do not have folds.
Do arteries have valves?
No.
Which artery type contains the most smooth cells?
Muscular arteries.
Do large veins have valves?
No.
What is the vasa vasorum?
Blood vessels that supply the walls of large arteries and veins.
Describe the movement of lymph from collection. (4)
- Lymphatic capillaries. 2. Collecting lymphatic vessels. 3. Lymph trunks. 4. Lymph ducts.
What is hematopoiesis?
The process of blood cell formation.
What kind of stem cell ultimately gives rise to all blood cells?
Hematopoietic stem cells.
What is anemia?
The condition marked by a decrease in the ability to deliver oxygen to tissues due to a decrease in the hematocrit, the hemoglobin content of the blood, or both.
What is fibrosis?
The formation of scar tissue.
